This invention relates particularly to breathing face masks which seal against the face of a user and exclude the ambient environment from those portions of the face which are confined by the mask.
It is important that a face mask properly fit the face of the wearer and the need for a good seal is self-evident. However, comfort in the fit of the mask on the face also is a significant factor because if the mask is not comfortable to wear it will bother and distract the user.
Generally, face masks are not custom made. Instead, they are made in only a very limited number of shapes and sizes, intended for use with a wide variety of facial shapes and sizes. The wide range in shapes and sizes of the human face make it difficult to provide a mask which will comfortably fit a variety of users.
U.S. Pat. No. 3,545,436--Holloway, issued Dec. 8, 1970 and pending U.S. patent application Ser. No. 707,221--Watkins filed July 21, 1976, both being assigned to the assignee of this application, disclose useful face mask arrangements in which a floating seal is suspended from a relatively rigid mask body in a manner to be comformable in sealing relation to the face of the user independently of the mask body. As the mask is positioned against the face, a hinge connecting the floating seal to the mask body resiliently yields and urges the floating seal against the face. As stated, a face piece mask or respirator should ideally fit all or most facial countours that are likely to be encountered during use. One method of accomplishing this is to provide the sealing area of the mask with a soft rolled edge or re-entrant flap. Such a soft flexible area allows the face piece to conform to the shape of the wearer's face and provide an air-tight seal. In regard to half face piece designs, a problem with respect to fitting many faces is encountered in the nose area, or more specifically, in the hollow at each side of the nose. At this point, on many faces, a sealing flap tends to be pulled away from the face at the deepest point of the hollow allowing air seepage past those two points.